Radio frequency hair removal tweezer

ABSTRACT

A radio frequency hair removal tweezer assembly having an accurately formed lead-conductor pad configuration for providing greater radio frequency transmission capability. A raised conductor surface and angular inclination of the pad members permits forceful grasping of the hair and improved radio frequency transmission down the hair shaft. An integrally molded unitary tweezer unit is positioned within a split two piece housing assembly and results in rapid and accurate assembly of the working components and elimination of high rejection rates of previous similar tweezer units.

BACKGROUND OF THE INVENTION

Radio frequency hair removal tweezers have been successfully used toremove unwanted hair by applying radio frequency energy through the tipof a hand-held hair grasping tweezer unit.

One of the most effective designs of this type of unit is that shown anddescribed in the Thomas L. Mehl U.S. Pat. Nos. 4,174,713, 4,174,714 and4,566,454. This unit permitted the user to come close to the skin withthe tweezer tip without bringing about a burn as a result of RF arcingto the skin surface. It also delivered more radio frequency energy downthe hair shaft, effectively inhibiting regrowth of the hair from thehair follicle.

Although the tweezer unit worked effectively, the design did not producemaximum power transfer to the hair and also brought about high rejectionrates of the production model.

SUMMARY OF THE INVENTION

Consequently, this invention is directed to providing a modified andimproved radio frequency hair removal tweezer unit which transmits radiofrequency energy more effectively, and which can be produced at a highproduction rate with a low percentage of rejections.

Further, this invention uses an improved radio frequency conductor wiredesign which more effectively transmits radio frequency waves to thehair shaft. It also provides improved tweezer arms which substantiallyenhance the ability to effectively grip the hair shaft by providing anangular relative orientation between opposed tweezer RF conducting padsat the tip of the tweezer for more effectively providing a forcefulcontact with the hair shaft.

Additionally, the conducting pads are arranged above the adjacentplastic tweezer arm material to avoid the possibility of that materialinterfering with complete closure of the tweezer pads about the hairshaft.

The tweezer of this invention also provides an instrument in which radiofrequency energy is always available for use with no need to provide aswitch element to interrupt radio frequency supplied to the radiofrequency conductor pads.

These and further features of this invention will become apparent fromthe drawings and the following description of the invention.

DESCRIPTION OF THE DRAWINGS

Referring particularly to the drawings, FIG. 1 is a cross-sectional viewof a hair in position within a tissue and held between the free engagingends of an RF radio frequency (RF) tweezer.

FIG. 2 is an enlarged partial view of FIG. 1 showing the manner in whichthe tweezer tips engage the hair shaft.

FIG. 3 is a plan view of one of the tweezer tips shown in FIG. 2.

FIG. 4 is a sectional view of the tweezer tip along line 4--4 of FIG. 3.

FIG. 5 is a side view of the radio frequency tweezer and holderassembly, showing the tweezer in cross-section.

FIG. 6 is a top view of the RF tweezer and holder assembly of FIG. 5.

FIG. 7 is an end view of the tweezer of FIG. 6.

FIG. 8 is a phantom view of the tweezer of FIG. 5 showing the electricalconnection to the RF tweezer.

DESCRIPTION OF THE INVENTION

Referring particularly to FIGS. 1 and 2, a section of tissue containinga hair generally indicated at 10 has the external portion 12 of the hairshaft extending upwardly from the skin surface, while the internalportion of 14 of the hair shaft extends downwardly beneath the skinsurface to the hair follicle 16. The hair has a central core section 18which conducts radio frequency energy along the length of the hair tothe hair follicle.

The external section of the hair shaft is shown grasped between the twoopposed tweezer arm ends 20 and 30.

The two opposed tweezer arms are each similar in construction and carryopposed metal RF frequency conducting pads, 22, 32, which contact andgrasp between them the external hair shaft portion 12. The pads aredisposed at a small angle with respect to each other and initially makecontact at their forward edges 24, 34, and then close into full contactwith other on flexure of the tweezer arms.

Both the tweezer arms are identical in construction.

The tweezer itself is an injection molded piece, which, as can be seenin FIGS. 5 through 8, is supported within the forward portion of ahad-held cylindrical handle. The tweezer itself is an injection moldedpiece with a central plug section from which both tweezer arms 20 and 30extend. The tweezer is slightly lager than an ordinary tweezer and ismade of a flexible plastic such as acrylic resin, or other moldedmaterial. The tweezer arms carry a wire conductor and have someflexibility.

The tip of the tweezer 21 is rounded and is slightly over 1/8 of an inchin width. The conducting pad 22 a flat conducting surface, which ispreferably gold plated. It has a rounded forward periphery 23 which isslightly greater than 1/8 of an inch in width, and extends about 3/16 ofan inch from the forward periphery 23 to the rear edge 24. Thesurrounding insulation of plastic around the pad is about 1/32 of aninch wider.

The conducting pad 24 is connected to an angled flat intermediateconnecting section which in turn is integral with the end of a circularsolid copper lead wire 26.

The conducting pad 22 and the intermediate connector section areproduced by inserting the end of a round wire copper lead into astamping die which, on closing, flattens the wire, forming the pad andintermediate connection sections on the end of the wire. This providesan accurate and closely dimensioned piece which can also be readily andaccurately positioned in an injection cavity mold.

It should be noted that the conducting pad surface, which is preferablygold plated, is also slightly raised above the surface of the plasticsurface of the tweezer as shown in FIG. 4 at 29 to provide a clearancewhich is no less than 1/32 of an inch. Because of the clearance, the twoopposed conductor pad surfaces can come together in non-interferingengagement, and as shown in FIG. 2, are sufficiently clear to permit theconducting pad forward surfaces 23 and 33 to come into initialengagement at a slight angle. Subsequent pressure on the tweezer arms 20and 30 flexes the two elongated arms, brining the full length of thesurfaces of the pads 22 and 32 into full and forceful engagement witheach other. This arrangement precludes the possibility of aninterference with full and complete closure that might possibly result,if the plastic material of the tweezer arm happened to be higher thanthe pad surface.

These figures illustrate the criticality of the dimension and thepositioning of the pads and their leads within the tweezer arm, sincethe width of the surrounding plastic is only about 1/32 of an inch. Theshape of the pad and integral lead permit it to be accurately positionedin the mold. Previously, this has not been possible. One of thedifficulties encountered was that due to the thinness of the tweezer armand the enclosing plastic surrounding the conductor and the conductingsurface at the tip of the tweezer, accurate positioning of the elementswas not always possible and the wire conductor and conducting surfacefrequently was not covered with the insulating plastic of the tweezer ormolding. Such tweezer pieces had to be rejected.

With the construction of this invention, in which the end of theconductor is accurately stamped in a tight tolerance press, to producethe combined pad and lead as a single accurate integral piece which canbe accurately positioned within the mold cavity, the problem encounteredwith the previous production item is avoided.

In addition, the approach of providing a fully single conductingpad-lead stamped piece for conducting the radio frequency, provides agood radio frequency wave guide configuration with more radio frequencycarrying capability, with less loss. Little change in sectionalconfiguration and no sharp break in RF path insures greater RF frequencytransmission to the surface of the pad. The pad surface itself, which ispreferably gold plated, also contributes to more effective powertransmission of the radio frequency to the hair itself. The usualfrequency applied to the lead 26 is 15,000 hertz at approximately 100volts.

The entire hand-held tweezer assembly is shown in FIGS. 5 through 8. Theinjection molded tweezer consisting of arms 20 and 30, and thecylindrical support base 40 fit into a split two piece cylindricalhandle housing formed by the two identical molded and split pieces 70and 80. These are snapped together along adjacent longitudinallyextending faces.

The tweezer assembly cylindrical section 40 is received within theforward cavity defined by the semi-cylindrical sections 72 and 82, asillustrated in FIGS. 5 and 6. The positive radio frequency lead 26 oftweezer arm 20 extends outwardly beyond the rearward surface 48 of thecylindrical tweezer base 40. The tweezer arms 20 and 30 are spacedsubstantially from each other at the front face indicated at 42 topermit the tweezers at their ends to move into engagement at an angularinclination for firm pad engagement. The flat side face 71 of thehousing piece 70 has a forward elongated semi-cylindrical receivingcavity 72 for receiving half of the tweezer section 40. A rear powerline receiving cavity 74 accommodates the internal radio frequencysupply line 64 of radio frequency supply cable 60. Conductor receivingsleeve 50 is disposed within the channel 76 and is interconnected withthe frequency supply wire 66 at 54.

In this tweezer modification, it is not necessary to have a power supplybutton. The power is continuously supplied to the lead wire Z6 of thetweezer arm Z0. It should also be noted that the conductor pad 32 oftweezer arm 30 has only a small lead 36. This is completely isolated,not being connected to either a ground or radio frequency supply cable.The tweezer has been found to work effectively with this electricalarrangement. Apparently, only a contact pad opposing the pad supplyingthe radio frequency energy in the opposing tweezer arm, is necessary.The rear external surface of the handle is tapered as indicated at 78.The pin members 79 extend outwardly from the flat side face 71 ofhousing 70. They extend into openings 89, not shown, in the opposingmatching surface 81 of the semi-cylindrical housing element 80.

Accordingly, the new tweezer design described provides greater hairgripping capability, and better radio frequency transmission through theconductor pad to the hair. This results in about a 1/3 or greaterreduction in the amount of time, originally 10 to 20 seconds, requiredfor removal of the hair.

The construction of this tweezer unit is simplified with threeaccurately molded major components which are accurately and readilyassembleable. The re-design of the tweezer itself provides a productionitem which will overcome the 20 to 25 percent rejection rate encounteredwith the previously designed tweezer.

While this invention has been described as having preferred design, itis understood that it is capable of further modification, uses and/oradaptations of the invention following in general the principle of theinvention and including such departures from the present disclosure ascome within known or customary practice in the art to which theinvention pertains, and as may be applied to the essential features setforth, and fall within the scope of the invention or the limits of theappended claims.

What is claimed is:
 1. A radio frequency hair removal tweezercomprising:a) a hand-held housing to which radio frequency energy issupplied which has a forward end supporting a pair of tweezer armsextending outwardly therefrom; b) the tweezer arms being a pair ofrelatively movable opposed and spaced flexible plastic members which aremovable into contact with each other at their opposed free ends at asmall angle with respect to each other; c) each of the tweezer arms attheir opposed free ends having a flat interior surface facing eachother; d) the facing interior surfaces having a radio frequencyconducting hair engaging metal conducting pad with a flat surface whoseperiphery is slightly spaced from the outer periphery of the flatinterior surface of the tweezer; e) each of the conducting pad surfacesbeing raised slightly above the flat interior surface of ht tweezer freeends, whereby the tweezer arms can bring the opposed pads together attheir extremities at a slight angle with no interference from theadjacent plastic surface to provide a firm forceful contact between theopposed conducting pad surfaces; and f) at least one of the tweezer armshaving a conducting pad lead wire which extends the length thereof andis connected with the conducting pad at the free end.
 2. The radiofrequency hair removal tweezer as set forth in claim 1, wherein:a) atweezer support base is disposed at the forward end of the housing fromwhich the tweezer arms extend; b) the tweezer support base and thetweezer arms being a unitary molded piece; and c) the tweezer supportbase having an electrical lead extending there through and beingintegral with the conducting pad lead wire.
 3. The radio frequency hairremoval tweezer as set forth in claim 2, wherein:a) the conducting padlead wire has an extended section which extends rearwardly of thetweezer support base; and b) the housing contains an electricalconnector receptacle which receives the extended section of theconducting lead wire.
 4. The radio frequency hair removal device as setforth in claim 1, wherein:a) the flat conducting surface of at least oneconducting pad has a gold plated conducting surface.
 5. The radiofrequency hair removal device as set forth in claim 1, wherein:a) theconducting pad is an integral continuous part of the conducting pad leadwire; b) the conducting pad being connected to the conducting pad leadwire through a flattened intermediate connection section; and c) theconducting pad and the intermediate flattened section, both being formedfrom an end portion of the conducting pad lead wire.
 6. The radiofrequency hair removal device as set forth in claim 1, wherein:a) thehand-held housing is an assembly of two matching substantially identicalhousing elements having corresponding engaging faces which meet along acommon substantially longitudinal plane.
 7. The radio frequency hairremoval tweezer as set forth in claim 6, wherein:a) each of the housingelements has an open semi-cylindrical cavity at the forward endreceiving cylindrical tweezer base element which supports the tweezerarms.
 8. The radio frequency hair removal device as set forth in claim7, wherein:a) one of the housing elements has plural outwardlyprojecting pins extending form a flat longitudinally extending engagingface; and b) the other housing element has a corresponding flat engagingface and plural pin receiving recesses in its corresponding flatengaging face which are disposed opposite from and receive the outwardlyextending pins from the one housing element.
 9. The radio frequency hairremoval tweezer as set forth in claim 1, wherein:a) the conducting padlead wire is directly connected continuously to a radio frequency powersupply line.
 10. The radio frequency hair removal tweezer as set forthin claim 1, wherein:a) the conducting pad lead wire and the radiofrequency conducting pad are a single integral element having good radiofrequency wave guide transmission characteristics.
 11. A radio frequencyhair removal tweezer comprising:a) a hand-held housing to which radiofrequency energy is supplied which has a forward end supporting a pairof tweezer arms extending outwardly therefrom; b) the tweezer arms beinga pair of relatively movable opposed and spaced flexible plastic memberswhich are movable into contact with each other at their opposed freeends at a small angle with respect to each other; c) each of the tweezerarms at their opposed free ends having a flat interior surface facingeach other; d) the facing interior surfaces having a radio frequencyconducting hair engaging metal conducting pad with a flat surface whoseperiphery is slightly spaced from the outer periphery of the flatinterior surface of the tweezer such that the two surfaces can bebrought into direct contact with each other; e) a conducting pad leadwire of solid metal cross-section disposed in one of the tweezer armsand has as an integral continuous part thereof forming a conducting pad;f) the conducting pad is connected to the conducting pad lead wirethrough a flattened intermediate and offsetting connection section; and,g) the conducting pad and the intermediate flattened offsetting sectionare both formed from an end portion of the conducting pad lead wire. 12.The radio frequency hair removal tweezer as set forth in claim 11,wherein:a) the flat surface of at least one conducting pad as a goldplated conducting surface; b) the hand-held housing is an assembly oftwo matching substantially identical housing elements havinglongitudinally engaging faces which meet along a common substantiallylongitudinal plane.